This invention relates to providing a further improved machine and method for producing in flexible material, especially a shoe component, a stiffened selected area thereof.
The invention more particularly is concerned with combining a thermoplastic adhesive while still largely molten with a predetermined surface of the area to be stiffened in such a fashion that the surface, including any irregularities therein, is in effect not only rendered substantially smooth, but will have a portion of diminishing stiffness by reason of a portion of the adhesive being formed during transfer to the area, while soft, and thus caused to taperingly merge with the surface.
In the prior art the following disclosures may in various respects be deemed relevant amongst United States Letters Patent, for example:
U.S. Pat. No. 3,277,867 -- Kilham et al., U.S. Pat. No. 3,605,151 -- Maifeld et al., U.S. Pat. No. 3,616,573 -- Chaplick et al., U.S. Pat. No. 3,442,743 -- Schultz et al., U.S. Pat. No. 3,523,814 -- Kamborian, U.S. Pat. No. 3,653,356 -- Brastow and, U.S. Pat. No. 3,795,466 -- Capuano
So far as known, few if any of the machines suggested by these disclosures other than possibly those of Kilham et al. and Chaplick et al. have found general and very wide acceptance in industry probably because they commonly are inconvenient in operation and/or fail to suitably deal with both regular and irregular sheet material. An important aspect in which the method teaching of the Chaplick et al. patent, commonly owned by the assignee of this invention, is relevant is its disclosure that the molten adhesive desirably should have a viscosity low enough to wet and adhere to the surface to be stiffened and high enough that it will not substantially penetrate the shoe component being stiffened.